Explain about contiguous memory allocation. Give the basic concepts about paging. Explain the basic concepts of segmentation. Explain the various page replacement strategies. Consider the following page-reference string: 1,2,3,4,2,1,5,6,2,1,2,3,7,6,3,2,1,2,3,6 How many page faults would occur for the following replacement algorithms, assuming frame size is 4. Remember that frames are initially empty.

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Fegore What is a process? A stub is included in the image for each library-routine reference. Compare User Threads and Kernel Threads. What do you mean by first fit? Now the freed frame can be used to hold the page for which the process faulted. What is the basic approach of Page Replacement?

Begins at the root and follows a path down to the specified file, giving the directory names on the path. Difference between stable storage and tertiary storage. What is meant by Stable Storage?

Define syste, waiting and spin lock. Operators batched together jobs with similar needs and suestion them through the computer as a group. Anna University — Mathematics 1 — January Que As a process enters a system, they are put into a job queue. Low-level formatting also sets aside spare sectors not visible to the operating system. Eventually, the first job finishes waiting and gets the CPU back.

Using c the valid-invalid bit traps illegal addresses. In case of system crash memory failurethe free-space list would not be lost as it would be if the bit map had been stored in main memory. What is a semaphore? Virtual memory is commonly implemented by demand paging. Questiion real time systems have more limited utility than do hard real-time systems.

The state of a process is defined in part by the current activity of that process. This process is called swapping. Define Logical Address and Physical Address. What is a pure demand paging? If the request cannot be granted immediately, then the requesting process must wait until it can acquire the resource.

What are the necessary conditions for a deadlock to occur? Which disk scheduling algorithm would be best to optimize the performance of oerating RAM disk? E Civil 5th Semester Question Define seek time and latency time. Switching the CPU to another process requires saving the state of the old process and loading the saved state for the new process. What is virtual memory? Explain about various Allocation Methods. What does the CPU do when there are no user programs to run? Each process executing the shared data variables excludes all others from doing so simultaneously.

What are the various page replacement algorithms used for page replacement? One opens it for reading, the other for writing.

Explain the various types of computer systems. Waiting processes may never again change state, because the resources they have requested are held by other waiting processes.

Each request requires the system consider the resources currently available, the resources currently allocated to each process, and the future requests and releases of each process, to decide whether the could be satisfied or must wait to avoid a possible future deadlock.

What is the principle disadvantage, other than cost, of the MB version? What are the various methods for free space management? A file contains either programs or data. What is co-operative process? Differentiate tightly coupled systems and loosely coupled systems. Operating system OS CS previous year question papers Write notes about the protection strategies provided for files. Discuss in detail about structure of page tables with appropriate examples.

Since segments vary in length, memory allocation is a dynamic storage-allocation problem. Time-sharing or multitasking is a logical extension of multiprogramming. Most 10 Related.



This scheme is known as sector sparing or forwarding. System Calls are also called as Monitor call or Operating-system function call. Several jobs are placed in bahk main memory and the processor is t p switched from job to job as needed to keep several jobs advancing while keeping the peripheral devices in use. In what ways the directory is implemented? The section of the code implementing this request is the entry section. A FIFO has properties identical to a pipe, except that it appears in the file system; thus, it can be opened using the open system call.


Tull Therefore they are fairly sophisticated. What are a Safe State and an Unsafe State? This ability to continue providing service is proportional to the surviving hardware is called graceful degradation. In multiprocessor systems, failure o;erating one processor will not halt the system, but only slow it down. Operating system OS CS previous year question papers The full bootstrap program is stored in a partition called the boot blocks, at fixed location on the disk.


What is an Operating System? An operating system is a program that manages the computer hardware. It also provides a basis for application programs and act as an intermediary between a user of a computer and the computer hardware. It controls and coordinates the use of the hardware among the various application programs for the various users. The OS acts as a manager for these resources so it is viewed as a resource allocator. What is the Kernel?



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